1. Field of the Invention
The present invention relates to a hybrid IC and an electronic device using the same, in particular this invention relates to a hybrid IC having connection terminals for connecting the hybrid IC to the surface of a printed circuit board. The invention also relates to an electric device using such hybrid IC.
2. Description of the Related Art
FIG. 13 is a perspective view illustrating several connecting terminals provided on a conventional hybrid IC. As shown in FIG. 13, each clip terminal 60 serving as a connection terminal is formed by bending a metal plate into a generally S-like shape, so as to form three mutually parallel plates 60a, 60b, 60c, and two connecting plates 60d, 60e for connecting together the plates 60a, 60b, 60c, thereby presenting a clip-like connection terminal. A U-shaped portion of the clip terminal 60 consisting of plates 60a, 60d and 60b, is adapted to receive and hold an end portion of a hybrid IC circuit board 61. On either side of the clip terminal 60, there is formed on the circuit board 61 an electrode 61a for solderring connection or for electric connection. In this way, the clip terminal 60 may be soldered at a predetermined position, so as to be connected and fixed thereon. When a hybrid IC fixedly equipped with a plurality of clip terminals 60 is to be attached on to the surface of a printed circuit board (not shown), the plate 60c of each clip terminal 60 is mounted on the electrodes formed on the printed circuit board corresponding to the clip terminal 60 of the hybrid IC. Thus, the hybrid IC and the printed circuit board may be combined together by means of solderring.
FIG. 14 is a perspective view illustrating several connecting terminals provided on another conventional hybrid IC. As shown in FIG. 14, a connector block 70 serving as a connection terminal, comprises a plurality of electrically insulating square pillar members 70a, a plurality of terminal electrodes 70b surrounding the square pillar member 70a. A plurality of electrodes 71a are provided on the surface of the hybrid IC circuit board 71, with each electrode 71a aligned and in contact with a corresponding terminal electrode 70b of the connector block 70. Thus, with the connector block 70 mounted on the circuit board 71, each electrode 71a may be made into a fixed connection with a corresponding terminal electrode 70b, by means of solderring.
When the hybrid IC, with the connector block 70 fixedly attached on its circuit board 71, is to be attached on to a printed circuit board (not shown), the circuit board 71 shown in FIG. 14 shall be made upside down so that the connector block 70 will be mounted on the underside of a printed circuit board. Further, the printed circuit board is also equipped with a plurality of electrodes corresponding to the terminal electrodes 70b of the connector block 70. In fact, these electrodes of the printed circuit board may be fixedly connected with the corresponding terminal electrodes 70b on the circuit board 71, also by means of solderring.
FIG. 15 is a perspective view illustrating several connection terminals provided on a further conventional hybrid IC, which has been disclosed in Japanese Unexamined Patent Publication No. 1-244693. As shown in FIG. 15, a plurality of electrically conductive cubic members 80 each serving as a connection terminal, are provided on a circuit board 81. Each cubic member 80 is formed by a rectangular parallelepiped which is electrically conductive at least on its entire surface. Further, a plurality of electrodes 81a each for mounting an electrically conductive cubic member 80, are provided on the surface of the hybrid IC circuit board 81. Thus, these electrodes 81a and the electrically conductive cubic members 80 may be connected together by means of solderring.
When the hybrid IC, having a plurality of electrically conductive cubic members 80 fixedly attached on its circuit board 81, is to be attached on to a printed circuit board (not shown), a circuit board 81 shown in FIG. 15 shall be turned upside down so that the electrically conductive cubic members 80 will be mounted on the underside of a printed circuit board. Further, the printed circuit board is also equipped with a plurality of electrodes corresponding to the electrically conductive cubic members 80. In fact, these electrodes of the printed circuit board may be fixedly connected with the corresponding cubic members 80 on the circuit board 81, also by way of solderring.
However, the above prior arts shown in FIGS. 13-15 have some problems which will be discussed in detail in the following.
Namely, with the clip type terminals 60 shown in FIG. 13, as related above, it is necessary to provide an electrode 61a (for solderring connection) on either side of the clip terminal 60 on the circuit board 61. As a result, in solderring connection areas for connecting the plates 60a of the clip type terminals 60, it is not allowed to mount other electronic elements, thus it is difficult to produce a hybrid IC having a high density. Further, since the plate 60a of each clip type terminal 60 has a certain thickness which, upon solderring, will project upwardly and laterally beyond the upper surface of the circuit substrate board 61, it is difficult to produce a hybrid IC with a compact size. Moreover, since some additional fixing structures in connection with the circuit substrate board 61 are usually different from other electronic elements which are to be fixedly mounted on the hybrid IC, it is necessary not only to have a process for connecting these electronic elements to the hybrid IC, but also necessary to have at least another process to complete a desired solderring connection between these electronic elements and the above-mentioned additional fixing structures (which are in fact for use in connecting each clip type terminal 60 to the circuit substrate board 61). As a result, it is difficult to reduce the cost for manufacturing such hybrid IC.
With the connector block shown in FIG. 14, as related above, since a plurality of terminal electrodes 70b are provided on one square pillar member 70a, it is not allowed to remove one or more terminal electrodes 70b even if they have become not needed any more. This, however, will cause a necessity of providing other terminals such as electrodes 71a on the circuit substrate board 71, hence making it difficult to produce a hybrid IC with a high density. Further, since the connector block 70 has a high rigidity, after the hybrid IC is installed on to a printed circuit board, a positional relationship between the hybrid IC and the printed circuit board will be fixed. As a result, a possible stress caused due to a possible deflection of the printed circuit board will propagate completely to the hybrid IC, causing the hybrid IC to deflect and thus resulting in a damage to the hybrid IC. In more detail, a connection between the connector block 70 and the circuit substrate board 71, and a connection between the connector block 70 and the printed circuit board (not shown), will be broken and thus cause a damage to the connector block 70 itself, rendering it difficult to obtain a reliability for thus produced electronic device.
With the electrically conductive cubic members 80 shown in FIG. 15, as related above, since each cubic member 80 has a similar rigidity as the above connector block 70 (shown in FIG. 14), it is impossible to absorb a stress caused by a possible deflection of a printed circuit board (not shown), rendering it difficult to obtain a reliability for thus produced electronic device.
Further, referring to FIG. 16, when a reflow-solderring treatment is performed to attach an electrically conductive cubic member 80 to a circuit substrate body 81, since each cubic member 80 is small and hence is light in weight, and since a contact surface for each cubic member 80 to contact a circuit board 81 is a flat surface, the cubic member 80 is likely to float upwardly in a melt solder 82, causing the cubic member 80 to get inclined and then fixed in an inclined position with respect to the circuit board 81.